title: Diagnosis of Vibrio cholerae O1 infection in Africa.
abstract: Isolation of Vibrio cholerae O1 is necessary for cholera outbreak confirmation. Rapid diagnostic testing of fecal specimens, based on lipopolysaccharide detection of V. cholerae O1 or O139, may assist in early outbreak detection and surveillance. Cary-Blair transport medium is recommended for specimen transport. Filter paper, although used in epidemics, needs evaluation against rectal swab specimens. Fecal specimens are subcultured onto selective and nonselective media, including 5% blood agar and TCBS agar, for detection of V. cholerae O1 or O139. Suspicious, oxidase-positive isolates are serotyped in monovalent antisera. Antimicrobial-susceptibility testing is performed to detect resistance. Molecular characterization supports phenotypic identification and outbreak investigations. The presence of genes encoding cholera toxin, lipopolysaccharide, and El Tor biotype traits can be confirmed. Standardized pulsed-field gel electrophoresis analysis facilitates strain comparison. Quality management ensures reliability of results through validation and verification of functional laboratory equipment; quality control of testing procedures, laboratory reagents, and consumables; and participation in proficiency-testing schemes.
authors.affiliation: Centre for Enteric Diseases.
authors.forename: Karen H
authors.initials: KH
authors.lastname: Keddy
authors.forename: Arvinda
authors.initials: A
authors.lastname: Sooka
authors.forename: Michele B
authors.initials: MB
authors.lastname: Parsons
authors.forename: Berthe-Marie
authors.initials: BM
authors.lastname: Njanpop-Lafourcade
authors.forename: Kaye
authors.initials: K
authors.lastname: Fitchet
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Smith
mesh_terms: D000349:Africa / Q000453:epidemiology; D002771:Cholera / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology*; D005243:Feces / Q000382:microbiology; D006801:Humans; D013048:Specimen Handling / Q000379:methods; D041241:Vibrio cholerae O1 / Q000302:isolation & purification*
keywords: Africa; Vibrio cholerae O1; antimicrobial susceptibility testing; cholera; diagnostics; molecular diagnostics; quality management; rapid diagnostic tests